Funny you mention that one .. I had a DNF on it last saturday 🙂 .. I have to admit I didn’t spend a lot of time on it as I was also doing some letterboxes and was running out of time. It also did look like a lot of that area was old buildings & walls etc .. I wasn’t really expecting a cache to be hidden in those.
And you mention adders – one of my Chocolates got bitten by one in that area last year (it was the other side of great Gnats hill in the Langcombe valley). We were lucky she happened to be on medicines to boost her joints as she is getting slightly arthritic and this somehow countered the venom a bit the vet said. She managed to walk back all the way to the scout hut before going into shock.